Birds have lightweight skeletons made of hollow or partly hollow bones, supported by strong internal braces. These bones are strong but still very light. With their special wing shapes and powerful chest muscles, these features help birds fly and stay in the air.
Feathers serve important functions for both songbirds and ducks, including flight, insulation, waterproofing, camouflage, and attracting mates through display.
Birds do not have teeth to chew their food, but they have a gizzard. The gizzard is a strong, muscular part of their stomach. It grinds up tough foods like seeds, grains, and even small shells. Birds often swallow small stones to help their gizzard break down food.
Birds have different shapes of beaks and bills, based on what they eat. Songbirds with cone-shaped beaks can open and eat seeds, while birds with thin beaks can catch and eat insects. Some ducks have wide, flat bills with comb-like edges that help them filter plants from the water. Other ducks have sharp, jagged bills that help them catch and hold onto fish.
The shape of a bird's foot is another important adaptation. Most songbirds have three toes in front and one in back, which helps them grip branches and perch safely. Ducks have big, webbed feet that act like paddles, helping them swim and move easily in the water. Their toes fold back when they pull their feet up to swim faster.